Gene flow in a national cross-breeding beef population

Area of Science:

• Animal Genetics
• Livestock Breeding
• Population Genetics

Background:

• Effective genetic improvement and monitoring of beef cattle genetic resources necessitate a thorough understanding of the population's genetic makeup.
• The UK beef industry exhibits a unique breeding structure with considerable interaction between beef and dairy cattle populations.

Purpose of the Study:

• To investigate gene flow within the UK beef cattle population.
• To estimate the breed composition of commercial beef breeding cows, breeding bulls, and the prime slaughter population.
• To assess the influence of dairy breeds and the effectiveness of selection index technology in UK beef production.

Main Methods:

• Utilized British Cattle Movement Service records as the primary data source.
• Triangulated data with UK government statistics, industry information, and existing literature.
• Estimated breed composition and analyzed breeding bull sale results to evaluate selection index effectiveness.

Main Results:

• Cross-bred animals constitute 85% of commercial beef breeding cows and 94% of prime slaughter populations.
• Holstein/Friesian genetics are prevalent (33% in cows, 28% in slaughter population), followed by Limousin, Charolais, Simmental, Angus, and Belgian Blue.
• Dairy breeds, primarily Holstein/Friesian, significantly influence beef genetics, with 74% of maternal grand dams in the prime slaughter population being Holstein/Friesian.
• Natural service bulls are the most significant genetic contributors (47.8%), while artificial insemination and dairy breeds contribute 16.6% and 35.6%, respectively.

Conclusions:

• The UK beef population is heavily cross-bred, with substantial genetic input from dairy breeds, particularly Holstein/Friesian.
• Non-native beef breeds and dairy genetics play a dominant role in the UK beef industry's genetic landscape.
• Selection index technology shows a moderate but significant correlation with breeding bull sale prices, indicating its utility in genetic improvement.